FOREVER YOUNG?

by Finlay Macdonald

Regular exercise and a healthy diet are keys to a longer life, but what if we really could hold back the effects of age?

Science is making huge strides in anti-aging research, says the University of Illinois’s Professor S. Jay Olshansky, and the goal is to prolong the healthy years of life, not to make old age last longer.

First things first – what do we know (or not know) about how and why we age?

In humans and most other sexually reproducing species, aging is an inadvertent byproduct of fixed genetic programs for early life developmental events (growth, development, reproduction). Those programs were fixed by evolution in accordance with the hostility of the environment when each species arose. It's the "how" question, the mechanisms involved – that are not yet fully understood.

Why do our genes allow us to age, then?

Our genes serve to take us into adulthood, the stage at which we are fertile and able to reproduce. Genes are there for growth, development, and reproduction. The fact that our lifespan is limited, almost as a side-effect, seems less like an intentional product of evolution, but in fact it is a product of evolutionary neglect – not intent. There are no genes with the specific purpose of limiting life, but there are biological clocks in earlier stages of life that inadvertently set limits to longevity.

If aging is essentially about gradual cellular deterioration, will genetics be the key to slowing the process?

Yes. The degree to which maintenance and repair mechanisms operate is likely to be driven by genes. There are lots of theories as to how and why we age, but I think it’s significant that scientists are for the first time ever in a position to make organisms age more slowly in laboratory experiments. They have succeeded in prolonging the lives of worms, flies, mice, dogs, and monkeys. There is evidence that this will also be possible in humans within ten to 20 years.

People often assume anti-aging science would prolong life at its end stages, but is that actually the right way to look at it?

Successful efforts to delay aging are intended to extend the period of healthy life, no matter where in the lifespan this might occur. Many people think of delayed aging as an extension of old age and the infirmities that accompany it. That is exactly the scenario we’re trying to avoid.

We know a healthy lifestyle – regular exercise and eating well – prolongs life; why should we want more than that?

The only outcome we're seeking in aging science is the extension of healthy life. If we live longer, that’ll be a bonus – just so long as the added survival time is composed mostly of healthy life.

We still hear talk of immortality – the “fountain of youth” – so what is your take on that?

Immortality should not even be in the vocabulary of scientists working in the field – I’m a bit surprised that anyone takes someone seriously when they use this term.

So what are the likely upper limits of human lifespan?

The upper limit on life expectancy for national populations is around 85 for men and women combined. Maximum lifespan – the tip of the tail of the survival distribution – is unlikely to exceed the lifespan of Jeanne Calment [the French super-centenarian with the longest confirmed human lifespan on record of 122 years, 164 days].

The media offers regular news stories about super old people – usually with various “secrets of youth” they supposedly represent. Do such people offer researchers clues?

Yes. While it's not productive to ask long-lived people what their secret to longevity is (their answers often involve unhealthy behavioral risk factors), the clues are likely to be contained within their genome. So yes, this subgroup of the population is worthy of additional study.

Modern medicine is hyper-specialized, yet old age is a combination of many things, so is it a matter of combining multiple disciplines, or a new approach entirely?

It is likely that an interdisciplinary approach is going to be most fruitful in successfully developing interventions that slow aging. We are indeed talking about a new approach to public health here. Think of a successful therapeutic intervention in aging as a much more powerful form of Primary Prevention.

‘‘ Many think of delayed aging as an extension of old age and its infirmities. That is the scenario we're trying to avoid. ’’

-Dr. S. Jay Olshansky

Pharmacy shelves are full of “anti-aging” potions and other supposed miracle cures; do these reflect the real science or is this just a vanity market?

There are no “potions” of any kind available today that have been demonstrated to delay aging in people. If anyone makes claims to the contrary, they're just trying to separate you from your money using pseudo-science.

We’ve also seen recent claims being made for various potential breakthroughs in anti-aging research – there’s NAD+, a cellular compound found in every cell in the body that is essential to life, and mTOR (also known as mammalian target of rapamycin), that has been confirmed to increase lifespan in mice. Do you think these or something similar will constitute a “big bang” in anti-aging research?

Yes. There have been a large number of developments in the field in recent years – many of which are outlined in our new book entitled Aging: The Longevity Dividend. There is likely to be a major breakthrough in one or more of these areas in the coming years.

How long before we know if such treatments work?

That’s hard to tell. The issue of time here involves the time it takes to conduct clinical trials to test for safety and efficacy of an intervention. We may already have a successful intervention in hand, but we won't know it until the research is in.

What of the argument that the planet is already headed for over-population, why do we want to stop people dying, or at least prolonging life and therefore increasing populations?

No one serious in the field is seeking the elimination of death; immortality or radical life extension are not in the cards and we shouldn't even be talking about it. Successful efforts to slow aging will indeed produce more healthy older people who survive a bit longer than would otherwise be the case, but the effect on population growth would be about the same as a cure for cancer. I don't recall a single instance of anyone complaining about how a cure for cancer would influence population growth.

Finally, what are the dangers that anti-aging technology becomes the privilege of super-rich, that we create a new class of longer-lived people?

Even if such an intervention first becomes available to the wealthy, this is not a reason to avoid pursuing it. Most major public health interventions are inequitably distributed when first developed (think of aspirin when it was first invented). Eventually, any new major health care development like the one we seek, will make its way to the vast majority of the population.